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  Subjects -> VETERINARY SCIENCE (Total: 214 journals)
Showing 1 - 63 of 63 Journals sorted alphabetically
Acta Scientiae Veterinariae     Open Access   (Followers: 2)
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brasilica     Open Access  
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 2)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 8)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 17)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 5)
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 11)
American Journal of Primatology     Hybrid Journal   (Followers: 14)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 31)
Analecta Veterinaria     Open Access  
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 169)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 3)
Animal Nutrition     Open Access   (Followers: 17)
Animal Reproduction     Open Access   (Followers: 3)
Animal Reproduction Science     Hybrid Journal   (Followers: 6)
Animals     Open Access   (Followers: 10)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 3)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 9)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 7)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access  
Ars Veterinaria     Open Access  
Asian Journal of Medical and Biological Research     Open Access   (Followers: 3)
Asian Journal of Poultry Science     Open Access   (Followers: 3)
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 5)
Australian Veterinary Journal     Hybrid Journal   (Followers: 24)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 8)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access   (Followers: 2)
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 2)
Bangladesh Veterinarian     Open Access  
BMC Veterinary Research     Open Access   (Followers: 14)
Brazilian Journal of Veterinary Medicine     Open Access  
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Open Access   (Followers: 1)
Buletin Veteriner Udayana     Open Access   (Followers: 3)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 2)
Bulletin of the Veterinary Institute in Pulawy     Open Access   (Followers: 1)
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 11)
Case Reports in Veterinary Medicine     Open Access   (Followers: 6)
Ciência Animal Brasileira     Open Access   (Followers: 1)
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access   (Followers: 3)
Companion Animal     Full-text available via subscription   (Followers: 9)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 6)
Equine Health     Full-text available via subscription   (Followers: 4)
Equine Veterinary Education     Hybrid Journal   (Followers: 9)
Equine Veterinary Journal     Hybrid Journal   (Followers: 18)
Ethiopian Veterinary Journal     Open Access   (Followers: 4)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
FAVE Sección Ciencias Veterinarias     Open Access  
Folia Veterinaria     Open Access  
Frontiers in Veterinary Science     Open Access   (Followers: 2)
GISAP : Biology, Veterinary Medicine and Agricultural Sciences     Open Access  
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 8)
ILAR Journal     Hybrid Journal   (Followers: 2)
In Practice     Full-text available via subscription   (Followers: 2)
Indian Journal of Animal Sciences     Open Access   (Followers: 6)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Indonesia Medicus Veterinus     Open Access   (Followers: 1)
Intas Polivet     Full-text available via subscription   (Followers: 3)
International Journal of Tropical Veterinary and Biomedical Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
Irish Veterinary Journal     Open Access   (Followers: 5)
Japanese Journal of Veterinary Research     Open Access   (Followers: 1)
Journal of Veterinary Science & Technology     Open Access   (Followers: 7)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 6)
Journal of Advanced Veterinary Research     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 6)
Journal of Animal Science and Technology     Open Access   (Followers: 2)
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 8)
Journal of Buffalo Science     Hybrid Journal   (Followers: 2)
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 13)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 3)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 6)
Journal of Feline Medicine and Surgery Open Reports     Open Access   (Followers: 2)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 4)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 16)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 43)
Journal of the Selva Andina Research Society     Open Access   (Followers: 2)
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 2)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 7)
Journal of Veterinary Dentistry     Full-text available via subscription   (Followers: 1)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 7)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 17)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 26)
Journal of Veterinary Medical Education     Partially Free   (Followers: 11)
Journal of Veterinary Medicine     Open Access   (Followers: 13)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 10)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 6)
Journal of Veterinary Research     Open Access   (Followers: 2)
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 5)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 7)
Jurnal Agripet     Open Access   (Followers: 1)
Jurnal Ilmu dan Kesehatan Hewan (Veterinary Science and Medicine Journal)     Open Access   (Followers: 1)
Jurnal Medika Veterinaria     Open Access  
Jurnal Sain Veteriner     Open Access  
Jurnal Veteriner     Open Access   (Followers: 1)
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Livestock     Full-text available via subscription   (Followers: 2)
Macedonian Veterinary Review     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 4)
Medical Mycology Case Reports     Open Access  
Medicina Veterinária (UFRPE)     Open Access  
Microbes and Health     Open Access   (Followers: 1)
New Zealand Veterinary Journal     Full-text available via subscription   (Followers: 12)
New Zealand Veterinary Nurse     Full-text available via subscription   (Followers: 2)
Nigerian Veterinary Journal     Open Access  
Nutrición Animal Tropical     Open Access   (Followers: 2)
Onderstepoort Journal of Veterinary Research     Open Access   (Followers: 5)
Open Access Animal Physiology     Open Access   (Followers: 4)
Open Journal of Animal Sciences     Open Access   (Followers: 4)
Open Journal of Veterinary Medicine     Open Access   (Followers: 3)
Pesquisa Veterinária Brasileira     Open Access  
pferde spiegel     Hybrid Journal  
Polish Journal of Veterinary Sciences     Open Access   (Followers: 2)
Preventive Veterinary Medicine     Hybrid Journal   (Followers: 11)
REDVET. Revista Electrónica de Veterinaria     Open Access  
Reproduction in Domestic Animals     Hybrid Journal   (Followers: 1)
Research in Veterinary Science     Hybrid Journal   (Followers: 10)
Research Journal of Veterinary Sciences     Open Access   (Followers: 8)
Revista Acadêmica : Ciência Animal     Open Access  
Revista Brasileira de Ciência Veterinária     Open Access  
Revista Brasileira de Higiene e Sanidade Animal     Open Access   (Followers: 1)
Revista Brasileira de Parasitologia Veterinaria     Open Access  
Revista Brasileira de Zootecnia     Open Access   (Followers: 2)
Revista Ciencias Veterinarias     Open Access  
Revista Científica     Open Access  
Revista Colombiana de Ciencias Pecuarias (Colombian journal of animal science and veterinary medicine)     Open Access   (Followers: 1)
Revista Complutense de Ciencias Veterinarias     Open Access  
Revista da Sociedade Brasileira de Ciência em Animais de Laboratório     Open Access  
Revista de Ciência Veterinária e Saúde Pública     Open Access  
Revista de Educação Continuada em Medicina Veterinária e Zootecnia     Open Access  
Revista de Investigaciones Veterinarias del Perú     Open Access  
Revista de Medicina Veterinaria     Open Access  
Revista de Salud Animal     Open Access  
Revista Mexicana de Ciencias Pecuarias     Open Access   (Followers: 1)
Revista MVZ Córdoba     Open Access  
Revista Veterinaria     Open Access  
Revue Marocaine des Sciences Agronomiques et Vétérinaires     Open Access  
Revue Vétérinaire Clinique     Full-text available via subscription  
SA Stud Breeder / SA Stoetteler     Full-text available via subscription  
Schweizer Archiv für Tierheilkunde     Hybrid Journal  
Science and Animal Health     Open Access  
Scientific Journal of Animal Science     Open Access   (Followers: 5)
Scientific Journal of Veterinary Advances     Open Access   (Followers: 1)
Small Ruminant Research     Hybrid Journal   (Followers: 3)
South African Journal of Wildlife Research     Open Access   (Followers: 1)
Spei Domus     Open Access  
Tanzania Veterinary Journal     Full-text available via subscription   (Followers: 1)
team.konkret     Open Access  
The Dairy Mail     Full-text available via subscription   (Followers: 2)
The Professional Animal Scientist     Hybrid Journal  
Theriogenology     Hybrid Journal   (Followers: 1)
Tierärztliche Praxis Großtiere     Hybrid Journal  
Tierärztliche Praxis Kleintiere     Hybrid Journal  
Topics in Companion Animal Medicine     Hybrid Journal   (Followers: 3)
Transboundary and Emerging Diseases     Hybrid Journal   (Followers: 4)
Trends in Parasitology     Full-text available via subscription   (Followers: 12)
Tropical Animal Health and Production     Hybrid Journal  
Tropical Animal Science Journal     Open Access   (Followers: 2)
Tropical Veterinarian     Full-text available via subscription   (Followers: 1)
veterinär spiegel     Hybrid Journal   (Followers: 1)
Veterinaria     Open Access   (Followers: 1)
Veterinária e Zootecnia     Open Access  
Veterinária em Foco     Open Access  
Veterinaria México     Open Access  
Veterinária Notícias     Open Access  
Veterinarski Glasnik     Open Access  
Veterinary Anaesthesia and Analgesia     Hybrid Journal   (Followers: 11)
Veterinary and Comparative Oncology     Hybrid Journal   (Followers: 12)
Veterinary and Comparative Orthopaedics and Traumatology (VCOT)     Hybrid Journal   (Followers: 6)
Veterinary Clinical Pathology     Hybrid Journal   (Followers: 7)
Veterinary Clinics of North America: Equine Practice     Full-text available via subscription   (Followers: 11)
Veterinary Clinics of North America: Exotic Animal Practice     Full-text available via subscription   (Followers: 6)
Veterinary Clinics of North America: Food Animal Practice     Full-text available via subscription   (Followers: 6)
Veterinary Clinics of North America: Small Animal Practice     Full-text available via subscription   (Followers: 21)
Veterinary Dermatology     Hybrid Journal   (Followers: 7)
Veterinary Immunology and Immunopathology     Hybrid Journal   (Followers: 12)
Veterinary Journal     Hybrid Journal   (Followers: 17)
Veterinary Medicine and Animal Sciences     Open Access   (Followers: 4)
Veterinary Medicine and Science     Open Access   (Followers: 2)
Veterinary Medicine International     Open Access   (Followers: 6)
Veterinary Medicine: Research and Reports     Open Access   (Followers: 2)
Veterinary Microbiology     Hybrid Journal   (Followers: 8)
Veterinary Nurse     Full-text available via subscription   (Followers: 4)
Veterinary Nursing Journal     Hybrid Journal   (Followers: 3)

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Journal Cover Veterinary Microbiology
  [SJR: 1.381]   [H-I: 98]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
   Published by Elsevier Homepage  [3175 journals]
  • Recombinant adenovirus-delivered soluble CD163 and sialoadhesin receptors
           protected pigs from porcine reproductive and respiratory syndrome virus
           infection
    • Authors: Wenlong Xia; Zhi Wu; Changming Guo; Shanyuan Zhu; Xinyu Zhang; Xiaoli Xia; Huaichang Sun
      Pages: 1 - 7
      Abstract: Publication date: June 2018
      Source:Veterinary Microbiology, Volume 219
      Author(s): Wenlong Xia, Zhi Wu, Changming Guo, Shanyuan Zhu, Xinyu Zhang, Xiaoli Xia, Huaichang Sun
      Porcine reproductive and respiratory syndrome (PRRS) is one of the most important swine diseases affecting pig industry worldwide. Sialoadehesin (Sn) and CD163 are the two specific receptors for PRRSV infection of porcine alveolar macrophages. Our previous study showed that the soluble Sn receptor Sn4D-Fc and soluble CD163 receptor SRCR59-Fc expressed by the two recombinant adenoviral (rAd) vectors have an additive anti-PRRSV effect in vitro. In the present study, rAd-Sn4D-Fc and rAd-SRCR59-Fc were inoculated into pigs, and the efficient expression of Sn4D-Fc and SRCR59-Fc proteins was detected by ELISA. Then, PRRSV-naïve pigs were inoculated with rAd-Sn4D-Fc and/or rAd-SRCR59-Fc before contagious infection with different PRRSV strains. Among the three rAd inoculation groups, simultaneous inoculation with the two rAd vectors provided the best protection against highly pathogenic JXA1 strain PRRSV, followed by rAd-SRCR59-Fc inoculation and rAd-Sn4D-Fc inoculation. Clinical observation and quantitative RT-PCR analyses showed that all of the double rAd-inoculated pigs (n = 9) survived from the contagious infection with highly pathogenic JXA1, JS07 or SH1705 strain PRRSV with significantly alleviated clinical scores, viremia, fecal viral emission and tissue virus loads. These data suggest that rAd-Sn4D-Fc and rAd-SRCR59-Fc can be developed further as the universal therapeutic vaccine to facilitate PRRSV eradication.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.006
      Issue No: Vol. 219 (2018)
       
  • Enhanced infection of avian influenza virus H9N2 with infectious
           laryngeotracheitis vaccination in chickens
    • Authors: Nagah Arafat; Abdelfattah H. Eladl; Basma H. Marghani; Mohamed A. Saif; Reham A. El-shafei
      Pages: 8 - 16
      Abstract: Publication date: June 2018
      Source:Veterinary Microbiology, Volume 219
      Author(s): Nagah Arafat, Abdelfattah H. Eladl, Basma H. Marghani, Mohamed A. Saif, Reham A. El-shafei
      Avian influenza and infectious laryngeotracheitis viruses are common causes of respiratory diseases in chickens with economical importance worldwide. In this study, we investigated the effect of experimental co-infection of avian influenza virus-H9N2 (AIV-H9N2) with infectious laryngeotracheitis virus (ILTV) live-attenuated vaccine (LAR-VAC®) on chickens. Four experimental groups were included in this study: negative control group, AIV-H9N2 group, AIV-H9N2+LAR-VAC® group, and LAR-VAC® group. AIV-H9N2 was inoculated intranasally to challenged groups at 35 days of age. On the same day, LAR-VAC® was ocularly administered to vaccinated groups. Chickens were observed for clinical signs, changes in body weight and mortality rates. Tissue samples, sera, tracheal and cloacal swabs, and blood were also collected at 3, 6, 9 and 12 days post-infection (PI). A significant increase in clinical signs and mortality rates were observed in the AIV-H9N2 + LAR-VAC® group. Moreover, chickens coinfected with AIV-H9N2 and LAR-VAC® showed a significant decrease in body weight and lymphoid organs indices. The tracheal gross and histopathological lesions and the shedding titer and period of AIV-H9N2 were significantly higher in AIV-H9N2 + LAR-VAC® group when compared to other groups. Furthermore, AIV-H9N2 infection leads to humoral and cellular immunosuppression as shown by a significant decrease in the CD4+/CD8+ ratio and antibody responses to ILTV and a significant increase in H/L ratio. In conclusion, this is the first report of co-infection of AIV-H9N2 and ILTV vaccine in chickens, which leads to increased pathogenicity, pathological lesions, and AIV-H9N2 shedding titer and period, which can lead to severe economic losses due to poor weight gain and mortality.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.009
      Issue No: Vol. 219 (2018)
       
  • Genomic characterization of coagulase-negative staphylococci including
           methicillin-resistant Staphylococcus sciuri causing bovine mastitis
    • Authors: Manouchehr Khazandi; Abd Al-Bar Al-Farha; Geoffrey W. Coombs; Mark O’Dea; Stanley Pang; Darren J. Trott; Ricardo R. Aviles; Farhid Hemmatzadeh; Henrietta Venter; Abiodun D. Ogunniyi; Andrew Hoare; Sam Abraham; Kiro R. Petrovski
      Pages: 17 - 22
      Abstract: Publication date: June 2018
      Source:Veterinary Microbiology, Volume 219
      Author(s): Manouchehr Khazandi, Abd Al-Bar Al-Farha, Geoffrey W. Coombs, Mark O’Dea, Stanley Pang, Darren J. Trott, Ricardo R. Aviles, Farhid Hemmatzadeh, Henrietta Venter, Abiodun D. Ogunniyi, Andrew Hoare, Sam Abraham, Kiro R. Petrovski
      Methicillin-resistant coagulase-negative staphylococci (MRCoNS) have recently emerged as a significant cause of bovine mastitis worldwide. Here we describe the isolation of MRCoNS from cases of bovine mastitis from a single dairy farm in Australia. Fourteen CoNS isolates were identified as MRCoNS on the basis of having an oxacillin MIC of ≥0.5 μg/mL. The isolates were speciated as S. chromogenes (n = 1) S. fleurettii (n = 1), S. haemolyticus (n = 2), S. sciuri (n = 5), S. simulans (n = 1) S. succinus (n = 2) and S. xylosus (n = 2). Five of the isolates (S. fleuretti, S. haemolyticus S. sciuri and two S. succinus) were mecA-positive. We also detected a previously described S. sciuri mecA homolog in four oxacillin-resistant S. sciuri isolates. The remainder of the putative MRCoNS did not contain any mecA-related resistance determinants in their genomes. Comparative genomic analysis of three previously published S. sciuri isolates, from humans, a squirrel and a cereal crop (rice), and a representative isolate from our study demonstrated clustering and a high degree of genetic homogeneity (>95%), suggesting S. sciuri has low host specificity. In conclusion, CoNS, in particular S. sciuri, may act as a reservoir for SCCmec elements that can easily be spread between different host species by direct cross-infection.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.004
      Issue No: Vol. 219 (2018)
       
  • Acclimation strategies in gilts to control Mycoplasma hyopneumoniae
           infection
    • Authors: Laura Garza-Moreno; Joaquim Segalés; Maria Pieters; Anna Romagosa; Marina Sibila
      Pages: 23 - 29
      Abstract: Publication date: June 2018
      Source:Veterinary Microbiology, Volume 219
      Author(s): Laura Garza-Moreno, Joaquim Segalés, Maria Pieters, Anna Romagosa, Marina Sibila
      Mycoplasma hyopneumoniae (M. hyopneumoniae) is the primary causative agent of enzootic pneumonia (EP), one of the most economically important infectious disease for the swine industry worldwide. M. hyopneumoniae transmission occurs mainly by direct contact (nose-to-nose) between infected to susceptible pigs as well as from infected dams to their offspring (sow-to-piglet). Since disease severity has been correlated with M. hyopneumoniae prevalence at weaning in some studies, and gilts are considered the main bacterial shedders, an effective gilt acclimation program should help controlling M. hyopneumoniae in swine farms. The present review summarizes the different M. hyopneumoniae monitoring strategies of incoming gilts and recipient herd and proposes a farm classification according to their health statuses. The medication and vaccination programs against M. hyopneumoniae most used in replacement gilts are reviewed as well. Gilt replacement acclimation against M. hyopneumoniae in Europe and North America indicates that vaccination is the main strategy used, but there is a current trend in US to deliberately expose gilts to the pathogen.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.005
      Issue No: Vol. 219 (2018)
       
  • Evolution in Europe of African swine fever genotype II viruses from highly
           to moderately virulent
    • Authors: Gallardo C.; Nurmoja I.; Soler A.; Delicado V.; Simón A.; Martin E.; Perez C.; Nieto R.; Arias M.
      Pages: 70 - 79
      Abstract: Publication date: June 2018
      Source:Veterinary Microbiology, Volume 219
      Author(s): Gallardo C., Nurmoja I., Soler A., Delicado V., Simón A., Martin E., Perez C., Nieto R., Arias M.
      Since its arrival in the Caucasus and Russia in 2007, African swine fever virus (ASFV) has spread widely and has now affected the EU countries of Estonia, Latvia, Lithuania, Poland and, more recently, the Czech Republic and Romania. The ever-increasing evidence of seropositive wild boar in certain areas suggests that some animals may be surviving for some time or could even be recovering from the disease. This could be due to acquired immunity after the primary infection and/or the presence of related viruses of reduced virulence. To assess these hypotheses, two ASFV field strains from Estonia were studied in vivo in two groups of domestic pigs. After an incubation period of 4 ± 1.6 days, the pigs inoculated intramuscularly with Es15/WB-Tartu 14 ASFV (group 2) developed clinical signs associated with acute disease and succumbed 7 and 11 days post infection (dpi). Pigs inoculated with Es15/WB-Valga-14 ASFV (group 1) had longer incubation times (8 days) than those in group 2 and developed variable clinical signs and lesions compatible with subacute and chronic forms of ASF; they succumbed at 11 and 25 dpi. The in-contact pigs in both groups became infected 7–14 days after exposure and exhibited variable clinical manifestations and pathological findings ranging from acute to chronic disease. Two animals per group recovered completely after infection and were protected against a subsequent homologous virus challenge-exposure performed at 78 dpi. Under experimental conditions, no transmission occurred from the survivors to susceptible sentinel pigs housed together with the survivors 137 days after the primary infection.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.001
      Issue No: Vol. 219 (2018)
       
  • Ovine Mannheimia haemolytica isolates from lungs with and without
           pneumonic lesions belong to similar genotypes
    • Authors: Andrés García-Alvarez; José Francisco Fernández-Garayzábal; Fernando Chaves; Chris Pinto; Dolores Cid
      Pages: 80 - 86
      Abstract: Publication date: June 2018
      Source:Veterinary Microbiology, Volume 219
      Author(s): Andrés García-Alvarez, José Francisco Fernández-Garayzábal, Fernando Chaves, Chris Pinto, Dolores Cid
      This study investigated the genetic characteristics of 121 ovine Mannheimia haemolytica isolates from lungs with (n = 75) and without pneumonic lesions (n = 46) using multilocus sequence typing (MLST), virulence-associated gene typing and pulsed-field gel electrophoresis (PFGE). Twelve STs were identified with most isolates (81%) belonged to ST16, ST28 and ST8. Analysis of the M. haemolytica MLST Database indicate a wide distribution of these genotypes in small ruminants, never reported in bovine isolates. This could suggest the adaptation of certain genetic lineages of M. haemolytica to small ruminants. e-BURST analysis grouped most STs into three clonal complexes (CC2, CC8 and CC28), consistent with a clonal population structure of M. haemolytica. Virulence-associated gene typing identified five virulence profiles in 64% and 65.1% of the M. haemolytica isolates from lungs with and without pneumonic lesions, respectively. These data suggest that M. haemolytica isolates from the lungs with and without pneumonic lesions are genetically homogeneous. By PGFE analysis a high level of genetic diversity was observed not only within isolates from lungs without pneumonic lesions but also among isolates from pneumonic lesions (GD 0.69 and GD 0.66, respectively; P > 0.05). These results indicate that multiple strains of M. haemolytica may be associated with individual cases of pneumonia in sheep.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.012
      Issue No: Vol. 219 (2018)
       
  • Oral vaccination with a live Salmonella Enteritidis/Typhimurium bivalent
           vaccine in layers induces cross-protection against caecal and internal
           organ colonization by a Salmonella Infantis strain
    • Authors: Venessa Eeckhaut; Freddy Haesebrouck; Richard Ducatelle; Filip Van Immerseel
      Pages: 7 - 12
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Venessa Eeckhaut, Freddy Haesebrouck, Richard Ducatelle, Filip Van Immerseel
      Salmonella is an important zoonotic agent, and poultry products remain one of the main sources of infection for humans. Salmonella Infantis is an emerging serotype in poultry worldwide, reflected by an increased prevalence in poultry flocks, on broiler meat and in human foodborne illness cases. In the current study, the efficacy of oral administration of a live monovalent Salmonella Enteritidis and a live bivalent Salmonella Enteritidis/Typhimurium vaccine, against a Salmonella Enteritidis and Infantis infection, was determined. Oral administration of the live vaccines to day-old chickens caused a decrease in caecal colonization by Salmonella Enteritidis, but not Infantis, at day 7, when challenged at day 2. Vaccination with the bivalent vaccine at day 1 resulted in a decreased spleen colonization by both Salmonella Infantis and Enteritidis. Twice (at day 1 and week 6) and thrice vaccination (at day 1, week 6 and 16) of laying hens with the bivalent vaccine resulted in a decreased caecal colonization by Salmonella Enteritidis and Infantis, and significantly lower oviduct colonization levels by Salmonella Enteritidis. These data show cross-protection against Salmonella Infantis by oral administration of live vaccine strains belonging to other serogroups.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.022
      Issue No: Vol. 218 (2018)
       
  • Potential transmission routes of Dichelobacter nodosus
    • Authors: Iwan Locher; Ladina Giger; Sara Frosth; Peter Kuhnert; Adrian Steiner
      Pages: 20 - 24
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Iwan Locher, Ladina Giger, Sara Frosth, Peter Kuhnert, Adrian Steiner
      Footrot caused by Dichelobacter nodosus is a highly contagious bacterial disease affecting the claw of sheep and the main cause of lameness in these animals. It is not only an economic burden but also a serious animal welfare issue. More information about the transmission of D. nodosus is needed for effective footrot control programs. We therefore determined the prevalence of D. nodosus in sheep presented at shows and markets where commingling of animals occurs. Furthermore, possible transmission vectors during foot trimming were investigated and trimming knife decontamination protocols evaluated. Sheep at six markets and four shows were sampled and tested for the presence of D. nodosus by real-time PCR. Different vectors, such as trimming knives were tested by real-time PCR and for viable D. nodosus by culture. The prevalence of virulent D. nodosus in sheep presented at shows and markets ranged from 1.7% to 100%. Regions with an ongoing control program showed significantly lower prevalence. After trimming, positive real-time PCR and culture results were obtained from the knives, the hands of the claw trimmers as well as removed claw horn material whereas boots were only positive by real-time PCR. In conclusion, markets and shows pose a risk for transmission of D. nodosus. The risk of transmission is particularly high during claw trimming and recommended measures to limit this risk include wiping the knife with a disinfection towel, wearing and changing gloves after every sheep, as well as proper disposal of trimmed and infectious horn.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.024
      Issue No: Vol. 218 (2018)
       
  • Isolation and characterization of pathogenic leptospires associated with
           cattle
    • Authors: Jarlath E. Nally; Richard L. Hornsby; David P. Alt; Darrell Bayles; Jennifer H. Wilson-Welder; Debra E. Palmquist; Nathan E. Bauer
      Pages: 25 - 30
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Jarlath E. Nally, Richard L. Hornsby, David P. Alt, Darrell Bayles, Jennifer H. Wilson-Welder, Debra E. Palmquist, Nathan E. Bauer
      Pathogenic leptospires colonize the renal tubules of reservoir hosts of infection, including cattle, and are excreted via urine. In order to identify circulating serovars of pathogenic leptospires in beef cattle, and their associated rates of urinary excretion, a cross sectional study was performed. Fifty urine samples were collected one day each month over 12 consecutive months (N = 600), directly from the bladder of beef cattle at a single slaughter facility and assessed for the presence of leptospires by culture and the fluorescent antibody test (FAT). Where possible, a matched serum sample was also collected for the microscopic agglutination test (MAT). Forty-three urine samples were either culture positive or FAT positive, indicating that 7.2% of sampled beef cattle were actively excreting leptospires in urine. Twenty-three urine samples were culture positive. Sequence analysis of 16S ribosomal DNA and secY indicated that all isolates were Leptospira borgpetersenii. Typing by serology indicated that all isolates were serogroup Sejroe. An overall seroprevalence of 20% (MAT ≥ 1:25) was determined; positive bovine sera was most reactive to serogroup Sejroe (serovar Hardjo) (8.1%), and serogroup Australis (serovar Bratislava) (6.7%). There was poor correlation between seroprevalence and excretion of leptospires since 18/43 (41.9%) cattle, which were positive by culture or FAT, were seronegative. The virulence of two selected isolates of L. borgpetersenii was confirmed by experimental infection in small animal models of infection. Results confirm that L. borgpetesenii continues to circulate in beef cattle and that multiple diagnostic assays are required to detect active shedding. These findings also highlight beef cattle as a reservoir host for the potential zoonotic transmission of leptospires.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.023
      Issue No: Vol. 218 (2018)
       
  • High prevalence of Mycobacterium genavense within flocks of pet birds
    • Authors: A. Schmitz; R. Korbel; S. Thiel; B. Wörle; C. Gohl; M. Rinder
      Pages: 40 - 44
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): A. Schmitz, R. Korbel, S. Thiel, B. Wörle, C. Gohl, M. Rinder
      Mycobacterium genavense is regarded as the primary cause of mycobacteriosis in psittaciform and passeriform birds, which are commonly kept as pets. In humans, Mycobacterium genavense is especially pathogenic for young, old, pregnant and immunocompromised people (YOPIs). In birds, only few studies, mainly case reports, exist and there is still little e information about occurrence and relevance of this zoonotic pathogen. In this first pilot study concerning the prevalence of Mycobacterium genavense within flocks of naturally infected pet birds, real-time PCR examinations of 170 individual passeriform and psittaciform birds, including commonly kept budgerigars, lovebirds and zebra finches as well as gold finches and weaver finches, were conducted to determine the infection rate in six different aviaries. Antemortem examinations of faeces and cloacal swabs were compared with postmortem examinations of tissue samples to evaluate the reliability of antemortem diagnostics. Additional ophthalmologic examinations were performed to evaluate their diagnostic potential. Molecular examinations for viral co-infections, including circovirus, polyomavirus and adenovirus, were conducted to identify potential risk factors. PCR results revealed a detection prevalence of Mycobacterium genavense in the flocks varying from 3% to 91% based on postmortem testing, while antemortem diagnostics of faecal samples and swabs showed 64% discrepant (false negative) results. Ophthalmologic examinations were not useful in identifying infected birds within the flocks. Viral co-infections, especially with polyomavirus, were common. It has to be assumed that Mycobacterium genavense infections are widespread and underdiagnosed in companion birds. Viral infections might be an important risk factor. There is urgent need to improve antemortem diagnostics.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.026
      Issue No: Vol. 218 (2018)
       
  • A T4virus prevents biofilm formation by Trueperella pyogenes
    • Authors: Vinícius da Silva Duarte; Roberto Sousa Dias; Andrew M. Kropinski; André da Silva Xavier; Camila Geovana Ferro; Pedro M.P. Vidigal; Cynthia Canedo da Silva; Sérgio Oliveira de Paula
      Pages: 45 - 51
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Vinícius da Silva Duarte, Roberto Sousa Dias, Andrew M. Kropinski, André da Silva Xavier, Camila Geovana Ferro, Pedro M.P. Vidigal, Cynthia Canedo da Silva, Sérgio Oliveira de Paula
      Trueperella pyogenes is an opportunistic pathogen of many animal species. It causes economic losses worldwide, through mastitis, metritis and mainly endometritis in dairy cows. The ability of this bacterium to form biofilms is implicated in chronic infections through hampering immune system recognition and antibiotic penetration. Since it is difficult to eradicate T. pyogenes infections with antibiotics, phage therapy presents itself as a non-toxic, effective and economically viable alternative. The present study evaluated the use of the bacteriophage vB_EcoM-UFV13 (UFV13) in the prevention of T. pyogenes biofilm development. Based upon two different approaches (crystal violet and sessile cell counting) we observed that only a multiplicity of infection (MOI) of 10 showed a statistically significant reduction in biofilm formation. Although the exact mechanisms of biofilm disruption and cell-adhesion inhibition have not been determined, genome sequence analysis of the Escherichia phage UFV13 revealed a repertoire of virion-associated peptidoglycan hydrolases (VAPGHs). The present study presents new findings regarding the disruption of biofilm formation of a Gram-positive bacterium. Subsequent transcriptomic and proteomic research will help us to understand the exact interaction mechanisms between UFV13 and T. pyogenes.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.025
      Issue No: Vol. 218 (2018)
       
  • Recombinant Newcastle disease virus (NDV) expressing Duck Tembusu virus
           (DTMUV) pre-membrane and envelope proteins protects ducks against DTMUV
           and NDV challenge
    • Authors: Minhua Sun; Jiawen Dong; Linlin Li; Qiuyan Lin; Junying Sun; Zhicheng Liu; Haiyan Shen; Jianfeng Zhang; Tao Ren; Chunhong Zhang
      Pages: 60 - 69
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Minhua Sun, Jiawen Dong, Linlin Li, Qiuyan Lin, Junying Sun, Zhicheng Liu, Haiyan Shen, Jianfeng Zhang, Tao Ren, Chunhong Zhang
      The newly emerged Duck Tembusu virus (DTMUV) is responsible for considerable economic loss in waterfowl-raising areas in China since 2010. Meanwhile, the virulent Newcastle disease virus (NDV) has also caused sporadic outbreaks in waterfowl. The individual vaccines against both diseases are available, however, there is no bivalent or combined vaccine for either disease. Here, we constructed a recombinant NDV-vectored vaccine candidate that expresses the pre-membrane (prM) and envelope (E) genes from DTMUV, designated as aGM/prM + E. The foreign prM and E proteins were stably expressed in aGM/prM + E and exhibited similar pathogenicity but higher growth kinetics than those of the parental virus. The aGM/prM + E carries a fusion cleavage site in accordance with avirulent viruses that have been frequently isolated from waterfowl, and induced remarkably (p < 0.001) higher NDV-specific hemagglutination inhibition (HI) titers than commercially available live NDV vaccines (LaSota strain). The aGM/prM + E also elicited significantly higher (p < 0.05) virus neutralization (VN) titers than commercially available DTMUV inactivated vaccines (HB strain). The aGM/prM + E not only provided complete protection against NDV challenge but also reduced the gross lesions on ovarian folliculi and provided 80% protection against DTMUV in ducks. We note that the aGM/prM + E vaccine can prevent challenged ducks from shedding of NDV and DTMUV. Our results suggest that the candidate vaccine aGM/prM + E would help decrease NDV and DTMUV transmissions in waterfowl raising areas in China.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.027
      Issue No: Vol. 218 (2018)
       
  • N-halamine incorporated antimicrobial nonwoven fabrics for use against
           avian influenza virus
    • Authors: Tian Ren; Teresa V. Dormitorio; Mingyu Qiao; Tung-Shi Huang; Jean Weese
      Pages: 78 - 83
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Tian Ren, Teresa V. Dormitorio, Mingyu Qiao, Tung-Shi Huang, Jean Weese
      Airborne pathogens are one of the most common avenues leading to poultry diseases. Preventing the avian influenza (AI) virus from entering the chicken hatchery house is critical for reducing the spread and transmission of AI disease. Many studies have investigated the incorporation of antimicrobials into air filters to prevent viruses from entering the indoor environment. N-halamines are one of the most effective antimicrobial agents against a broad spectrum of microorganisms. In this study, 1-chloro-2,2,5,5-tetramethyl-4-imidazolidinone (MC, a variety of N-halamine) was coated on nonwoven fabrics to give the fabric antimicrobial activity against the AI virus. Results showed that MC exhibited potent antiviral activity either in suspension or in the air. Higher concentrations of MC completely inactivated AI viruses and disrupted their RNA, preventing them from being detected by the real time reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Coating the fabrics with MC resulted in remarkably reduced presence of AI virus on the MC-treated fabric in a short period of time. Furthermore, aerosolized AI viruses were completely inactivated when they passed through filters coated with the MC compound. In addition, MC is not volatile and does not release any gaseous chlorine. The active chlorine in the MC compound is stable, and the coating procedure is straightforward and inexpensive. Therefore, this study validates a novel approach to reducing airborne pathogens in the poultry production environment.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.032
      Issue No: Vol. 218 (2018)
       
  • Development of Mycoplasma synoviae (MS) core genome multilocus sequence
           typing (cgMLST) scheme
    • Authors: Mostafa Ghanem; Mohamed El-Gazzar
      Pages: 84 - 89
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Mostafa Ghanem, Mohamed El-Gazzar
      Mycoplasma synoviae (MS) is a poultry pathogen with reported increased prevalence and virulence in recent years. MS strain identification is essential for prevention, control efforts and epidemiological outbreak investigations. Multiple multilocus based sequence typing schemes have been developed for MS, yet the resolution of these schemes could be limited for outbreak investigation. The cost of whole genome sequencing became close to that of sequencing the seven MLST targets; however, there is no standardized method for typing MS strains based on whole genome sequences. In this paper, we propose a core genome multilocus sequence typing (cgMLST) scheme as a standardized and reproducible method for typing MS based whole genome sequences. A diverse set of 25 MS whole genome sequences were used to identify 302 core genome genes as cgMLST targets (35.5% of MS genome) and 44 whole genome sequences of MS isolates from six countries in four continents were used for typing applying this scheme. cgMLST based phylogenetic trees displayed a high degree of agreement with core genome SNP based analysis and available epidemiological information. cgMLST allowed evaluation of two conventional MLST schemes of MS. The high discriminatory power of cgMLST allowed differentiation between samples of the same conventional MLST type. cgMLST represents a standardized, accurate, highly discriminatory, and reproducible method for differentiation between MS isolates. Like conventional MLST, it provides stable and expandable nomenclature, allowing for comparing and sharing the typing results between different laboratories worldwide.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.021
      Issue No: Vol. 218 (2018)
       
  • Formation of high-order oligomers is required for functional bioactivity
           of an African bat henipavirus surface glycoprotein
    • Authors: Laura Behner; Louisa Zimmermann; Marc Ringel; Michael Weis; Andrea Maisner
      Pages: 90 - 97
      Abstract: Publication date: May 2018
      Source:Veterinary Microbiology, Volume 218
      Author(s): Laura Behner, Louisa Zimmermann, Marc Ringel, Michael Weis, Andrea Maisner
      Hendra virus (HeV) and Nipah virus (NiV) are highly pathogenic henipaviruses originating from fruit bats in Australia and Asia that can cause severe infections in livestock and humans. In recent years, also African bat henipaviruses were identified at the nucleic acid level. To assess their potential to replicate in non-bat species, several studies were performed to characterize the two surface glycoproteins required for virus entry and spread by cell-cell fusion. It has been shown that surface expression and fusion-helper function of the receptor-binding G protein of Kumasi virus (KV), the prototypic Ghanaian bat henipavirus, is reduced compared to other non-African henipavirus G proteins. Immunostainings and pulse-chase analysis revealed a delayed export of KV G from the ER. As defects in oligomerization of viral glycoproteins can be responsible for limited surface transport thereby restricting the bioactivity, we analyzed the oligomerization pattern of KV G. In contrast to HeV and NiV whose G proteins are known to be expressed at a dimer-tetramer ratio of 1:1, KV G almost exclusively formed stable tetramers or higher oligomers. KV G also showed less stringent requirements for defined stalk cysteines to form dimers and tetramers. Interestingly, any changes in the oligomeric forms negatively affected the fusion-helper activity although surface expression and receptor binding was unchanged. This clearly indicates that the formation of mostly higher oligomeric KV G forms is not a deficiency responsible for ER retention, but is rather a basic structural feature essential for the bioactivity of this African bat henipavirus glycoprotein.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.031
      Issue No: Vol. 218 (2018)
       
  • Proposal of serovars 17 and 18 of Actinobacillus pleuropneumoniae based on
           serological and genotypic analysis
    • Authors: Janine T. Bossé; Yanwen Li; Rita Sárközi; László Fodor; Sonia Lacouture; Marcelo Gottschalk; Maria Casas Amoribieta; Øystein Angen; Katerina Nedbalcova; Matthew T.G. Holden; Duncan J. Maskell; Alexander W. Tucker; Brendan W. Wren; Andrew N. Rycroft; Paul R. Langford
      Pages: 1 - 6
      Abstract: Publication date: April 2018
      Source:Veterinary Microbiology, Volume 217
      Author(s): Janine T. Bossé, Yanwen Li, Rita Sárközi, László Fodor, Sonia Lacouture, Marcelo Gottschalk, Maria Casas Amoribieta, Øystein Angen, Katerina Nedbalcova, Matthew T.G. Holden, Duncan J. Maskell, Alexander W. Tucker, Brendan W. Wren, Andrew N. Rycroft, Paul R. Langford
      The aim of this study was to investigate isolates of Actinobacillus pleuropneumoniae previously designated serologically either as non-typable (NT) or as ‘K2:07’, which did not produce serovar-specific amplicons in PCR assays. We used whole genome sequencing to identify the capsule (CPS) loci of six previously designated biovar 1 NT and two biovar 1 ‘K2:O7’ isolates of A. pleuropneumoniae from Denmark, as well as a recent biovar 2 NT isolate from Canada. All of the NT isolates have the same six-gene type I CPS locus, sharing common cpsABC genes with serovars 2, 3, 6, 7, 8, 9, 11 and 13. The two ‘K2:O7’ isolates contain a unique three-gene type II CPS locus, having a cpsA gene similar to that of serovars 1, 4, 12, 14 and 15. The previously NT isolates share the same O-antigen genes, found between erpA and rpsU, as serovars 3, 6, 8, and 15. Whereas the ‘K2:O7’ isolates, have the same O-antigen genes as serovar 7, which likely contributed to their previous mis-identification. All of the NT and ‘K2:O7’ isolates have only the genes required for production of ApxII (apxIICA structural genes, and apxIBD export genes). Rabbit polyclonal antisera raised against representative isolates with these new CPS loci demonstrated distinct reactivity compared to the 16 known serovars. The serological and genomic results indicate that the isolates constitute new serovars 17 (previously NT) and 18 (previously ‘K2:O7’). Primers designed for amplification of specific serovar 17 and 18 sequences for molecular diagnostics will facilitate epidemiological tracking of these two new serovars of A. pleuropneumoniae.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.02.019
      Issue No: Vol. 217 (2018)
       
  • Anaplasma ovis genetic diversity detected by major surface protein 1a and
           its prevalence in small ruminants
    • Authors: Munir Aktas; Sezayi Özübek
      Pages: 13 - 17
      Abstract: Publication date: April 2018
      Source:Veterinary Microbiology, Volume 217
      Author(s): Munir Aktas, Sezayi Özübek
      Anaplasma ovis is a widely distributed tick-borne rickettsial pathogen of sheep, goats, and wild ruminants. The aims of this study were to assess the prevalence, associations of Anaplasma ovis in sheep and goats, as well as its genetic diversity based on analysis of the msp1α gene. A total of 416 DNA samples from sheep (n = 236) and goats (n = 180) from four provinces in southeastern Turkey were analyzed by PCR. The overall A. ovis prevalence was 18% (CI 14.4–22.1). The infection rates of A. ovis varied from 15.9% to 21.8% in sampled provinces, and they were not significantly different. There was no difference between Anaplasma ovis infection in sheep (20.3%, CI 15.4–26.0) and goats (15.0%, CI 10.1–21.1) or in infection rate of animals <1 year (21.8%, CI 14.9-30.1) compared to >1 year (16.4%, CI 12.4–21.2). A significant association between A. ovis infection and the presence of Rhipicephalus bursa and Rhipicephalus turanicus was observed (P < 0.05). Prevalence of A. ovis-positive animals was higher in animals showing co-infection with Babesia and Theileria compared to those not co-infected (P < 0.05). The Msp1a amino acid repeats were identified and used for the characterization of A. ovis strains. Forty partial msp1a gene sequences containing the repeated sequences of A. ovis were obtained, and 14 previously undescribed tandem repeats with 33 to 43 amino acids were found. Thirteen A. ovis genotypes were identified based on the structure of Msp1a tandem repeats. The majority of A. ovis isolates exhibited one Msp1a tandem repeat, with a maximum of three. This study revealed the Msp1a could be used as a marker for genotyping A. ovis, and high genetic diversity of A. ovis were found in small ruminants in Turkey.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.02.026
      Issue No: Vol. 217 (2018)
       
  • Diagnostics, epidemiological observations and genomic subtyping in an
           outbreak of pullorum disease in non-commercial chickens
    • Authors: Helena Eriksson; Robert Söderlund; Linda Ernholm; Lennart Melin; Désirée S. Jansson
      Pages: 47 - 52
      Abstract: Publication date: April 2018
      Source:Veterinary Microbiology, Volume 217
      Author(s): Helena Eriksson, Robert Söderlund, Linda Ernholm, Lennart Melin, Désirée S. Jansson
      Salmonella Gallinarum biovar Pullorum (S. Pullorum) is a poultry pathogen associated with significant economic losses and animal suffering. Strict eradication programmes have eliminated S. Pullorum from the commercial poultry sector in most regions, but occasional outbreaks still occur in the non-commercial population. In 2012, pullorum disease was diagnosed in a non-commercial flock in Sweden. Epidemiological, post-mortem and bacteriological investigations identified three more infected flocks. To study the epidemiological relationships between the flocks and evaluate different subtyping methods for S. Pullorum, 13 isolates from the four infected flocks were investigated by pulsed-field gel electrophoresis (PFGE) and multi-locus variable number tandem repeat analysis (MLVA). Four isolates collected from two non-commercial flocks in 2001 were also included. Six representative isolates from 2012 were further analysed by high-throughput sequencing. To differentiate between biovars Gallinarum and Pullorum, ten regions of difference (RODs) were investigated by in silico PCR. Three different PFGE-types were observed from the four epidemiologically linked farms in 2012 and MLVA further discriminated the isolates. SNP typing based on high-throughput sequencing clustered the four farms from the 2012 outbreak in two pairs. The PFGE, MLVA and high-throughput sequencing results suggested at least two different sources of infection or a common genetically mixed source in 2012. High-throughput sequencing is useful both for subtyping of S. Pullorum and may also be used for differentiating between the two biovars Pullorum and Gallinarum.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.02.025
      Issue No: Vol. 217 (2018)
       
  • Emergence of the colistin resistance gene mcr-1 and its variant in several
           uncommon species of Enterobacteriaceae from commercial poultry farm
           surrounding environments
    • Authors: Xiaoming Wang; Yao Wang; Yang Wang; Suxia Zhang; Zhangqi Shen; Shaolin Wang
      Abstract: Publication date: Available online 14 April 2018
      Source:Veterinary Microbiology
      Author(s): Xiaoming Wang, Yao Wang, Yang Wang, Suxia Zhang, Zhangqi Shen, Shaolin Wang
      The colistin resistance gene mcr-1 has been detected in multiple members of Enterobacteriaceae family. Here, we report the emergence of mcr-1 in Providencia alcalifaciens and a mcr-1 variant, named mcr-1.3, in Raoultella planticola. Both of the mcr-1-carrying plasmids in these two isolates belong to IncI2 type of plasmids, but they are different in sizes and genetic characteristics. We also detected the mcr-1 gene in one Enterobacter cloacae isolate, however, the mcr-1-carrying plasmid is distinct from the previous reports. Conjugation assay showed that mcr-1-carrying plasmids in P. alcalifaciens and E. cloacae were successfully transferred into recipient E. coli strains. It is worth noting that the transferability of mcr-1-carrying plasmid from E. cloacae was enhanced once it entered into E. coli hosts, which might further accelerate the dissemination of mcr-1 among Enterobacteriaceae. These findings further expand our knowledge of the mcr-1-carrying species in Enterobacteriaceae.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.002
       
  • Evidence for Involvement of the Fas BCAX Regulon in Capsule Synthesis by
           Streptococcus equi
    • Authors: Sridhar Velineni; John F. Timoney
      Abstract: Publication date: Available online 14 April 2018
      Source:Veterinary Microbiology
      Author(s): Sridhar Velineni, John F. Timoney
      The constitutively expressed hyaluronic acid capsule is an important virulence factor of Streptococcus equi, the cause of equine strangles. Study of the genomic sequence of CF22caps–, a non-encapsulated mutant of S. equi CF22 generated by gamma (Co60) irradiation revealed a non-sense mutation in fasC (SEQ_0302), a sensor kinase gene in FasBCAX an operon with an important regulatory role in expression of streptococcal secreted virulence and matrix binding proteins. The mutation was associated with a significant (p < .05) decrease in transcription of hasA, the synthase gene essential for hyaluronic acid synthesis and, conversely, with small increases in transcription of skc, covR and seM. The early growth phase of CF22caps– was also delayed compared to the CF22caps+ parent. In contrast to the human pathogen, S. pyogenes, capsule synthesis in S. equi therefore appears to be controlled by FasBCAX and not by CovRS.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.015
       
  • Live attenuated duck hepatitis virus vaccine in breeder ducks: protective
           efficacy and kinetics of maternally derived antibodies
    • Authors: Roh Jae-Hee; Kang Min
      Abstract: Publication date: Available online 14 April 2018
      Source:Veterinary Microbiology
      Author(s): Roh Jae-Hee, Kang Min
      Duck viral hepatitis type I is a rapidly spreading infection lethal in young ducklings, caused by the duck hepatitis A virus (DHAV). Vaccination of breeder ducks is a common practice to control DHAV. However, maintaining proper maternal antibody levels in large flocks is difficult. Therefore, a simple vaccination strategy that can induces stable high antibody levels through mass vaccination is desirable. We evaluated a DHAV vaccination strategy for breeder ducks involving oral administration under field conditions, and examined the kinetics of antibody response in the ducks and their progeny. The strategy included a primary intramuscular vaccination, followed by secondary and tertiary oral vaccinations. Five weeks after the primary vaccination, virus-neutralizing antibody titers increased by 8.4 ± 1.3 log2. The titers remained stable at around 9.0 ± 1.1 log2 for up to 36 weeks. None of the progeny died when challenged with virulent DHAV at 1, 7 or 14 days of age. The transfer percentage of antibodies from the breeder ducks to their progeny was 12.8 ± 3.0%. When antibody levels of the progeny were measured from the day of hatching to 20 days of age, the levels steadily declined, reaching a mean titer of 0 log2 at 20 days. The half-life of the maternally derived antibodies against DHAV was 3.4 ± 1.1 days. Our vaccination strategy might be effective in breeder ducks because it can be easily applied and induced strong immunity. Moreover, our results might provide a foundation for the mechanistic study of maternally derived antibodies in passive protection.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.021
       
  • Pathogenicity of blood orf virus isolates in the development of dairy goat
           contagious pustular dermatitis
    • Authors: Hong-Yu Cheng; Wei-Juan Li; Xing-Ming Li; Qin-Lei Fan; Xi-Dian Tang; Ming-Jie Liu; Wen-Tao Ma; De-Kun Chen
      Abstract: Publication date: Available online 13 April 2018
      Source:Veterinary Microbiology
      Author(s): Hong-Yu Cheng, Wei-Juan Li, Xing-Ming Li, Qin-Lei Fan, Xi-Dian Tang, Ming-Jie Liu, Wen-Tao Ma, De-Kun Chen
      Contagious pustular dermatitis is an exanthematous zoonotic disease caused by the orf virus. Pandemic outbreaks of this disease cause great economic losses, while the pathogenesis of this disease still remains obscure. In this study, blood samples were collected from 628 asymptomatic goats across China for PCR-based virus detection. We detected the orf virus in the blood of asymptomatic goats. Moreover, the orf virus obtained from the blood of infected goats was infectious and induced typical symptoms of contagious pustular dermatitis after inoculation of uninfected dairy goats. In summary, our data provide evidence that asymptomatic animals may be carriers of orf virus. Our findings should contribute to elucidating the details underlying the pathogenesis of contagious pustular dermatitis.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.020
       
  • Rabbit haemorrhagic disease: cross-protection and comparative
           pathogenicity of GI.2/RHDV2/b and GI.1b/RHDV lagoviruses in a challenge
           trial
    • Authors: Carlos Calvete; Manuel Mendoza; Ana Alcaraz; María P. Sarto; María P. Jiménez de Bagüés; Antonio J. Calvo; Fernando Monroy; Jorge H. Calvo
      Abstract: Publication date: Available online 13 April 2018
      Source:Veterinary Microbiology
      Author(s): Carlos Calvete, Manuel Mendoza, Ana Alcaraz, María P. Sarto, María P. Jiménez de Bagüés, Antonio J. Calvo, Fernando Monroy, Jorge H. Calvo
      European rabbits (Oryctolagus cuniculus) are severely affected by rabbit haemorrhagic disease (RHD). Caused by a lagovirus, the disease leads to losses in the rabbit industry and has implications for wildlife conservation. Past RHD outbreaks have been caused by GI.1/RHDV genotype viruses. A new virus belonging to the GI.2/RHDV2/b genotype emerged in 2010, quickly spreading and replacing the former in several countries; however, limited data are available on its pathogenicity and epidemiological factors. The present work extends these issues and evaluates cross-protection between both genotypes. Ninety-four and 88 domestic rabbits were challenged with GI.2/RHDV2/b and GI.1b/RHDV variant isolates, respectively. Cross-protection was determined by a second challenge on survivors with the corresponding strain. Mortality by GI.2/RHDV2/b was highly variable due to unknown individual factors, whereas mortality by GI.1b/RHDV was associated with age. Mortality in rabbits <4 weeks old was 84%, higher than previously reported. Cross-protection was not identical between the two viruses because the ratio of mortality rate ratios for the first and second challenges was 3.80 ± 2.68 times higher for GI.2/RHDV2/b than it was for GI.1b/RHDV. Rabbit susceptibility to GI.2/RHDV2/b varied greatly and appeared to be modulated by the innate functionality of the immune response and/or its prompt activation by other pathogens. GI.1b/RHDV pathogenicity appeared to be associated with undetermined age-related factors. These results suggest that GI.2/RHDV2/b may interact with other pathogens at the population level but does not satisfactorily explain the GI.1b/RHDV virus’s quick replacement.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.018
       
  • Identification of antigenic epitopes of monoclonal antibodies against the
           VP2 protein of the 25 serotype of bluetongue virus
    • Authors: Shuangyu Xie; Yiming Shi; Ruyue Gong; Wen Cui; Yanping Jiang; Min Liu; Li Wang; Han Zhou; Xinyuan Qiao; Yijing Li; Yigang Xu; Lijie Tang
      Abstract: Publication date: Available online 11 April 2018
      Source:Veterinary Microbiology
      Author(s): Shuangyu Xie, Yiming Shi, Ruyue Gong, Wen Cui, Yanping Jiang, Min Liu, Li Wang, Han Zhou, Xinyuan Qiao, Yijing Li, Yigang Xu, Lijie Tang
      Serious outbreaks of bluetongue, an arbovirus of domestic and wild ruminants caused by bluetongue virus serotypes (BTV), have occurred around the world. More than 27 distinct serotypes are recognized throughout the world. A new virus, BTV-25 (Toggenburg orbivirus [TOV]), was first detected in Switzerland, and has not yet been found in China. VP2 is an important outer shell protein that defines BTV serotypes and is, therefore, an ideal target antigen for serotype identification. To produce a monoclonal antibody against VP2 of BTV-25, the segment 2 gene was divided into three segments, cloned into pET-28a (+) and pMAL-c5X vectors, and the protein was expressed in E. coli BL21 with different tags. Monoclonal antibodies (mAbs) were prepared by using the purified His-25A, 25B, 25 C proteins as the immunogen and the purified MBP-25A, 25B, 25 C proteins as the detection antigen. Twelve hybridoma cell lines stably secreting mAbs against different VP2 segments of BTV-25 were produced. The segment 2 gene was cloned into pFastBacTMHT B vector and a positive recombinant plasmid pFastBac-VP2 was used to identify mAbs. The recombinant baculovirus BACV-VP2 and eukaryotic expression of protein VP2 were obtained by the recombinant bacmid BAC-VP2 transfected Sf9 insect cells; western blotting showed that only eight mAbs were reactive. Finally, we identified the epitopes of VP2 recognized by three specific mAbs (25 A-2B6, 25B-2G3, 25 C-4B2) using phage display technology. The linear epitopes of VP2 protein were “359LYP361”, “580NT581”, “620TFR622”. The preparation of mAbs and identification of the epitopes provided a foundation to analyze VP2, and may assist in the serological diagnosis of BTV-25.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.008
       
  • Presence of Helicobacter and Campylobacter species in faecal samples from
           zoo mammals
    • Authors: C. De Witte; C. Lemmens; B. Flahou; P. De Laender; T. Bouts; F. Vercammen; R. Ducatelle; A. Smet; F. Haesebrouck
      Abstract: Publication date: Available online 11 April 2018
      Source:Veterinary Microbiology
      Author(s): C. De Witte, C. Lemmens, B. Flahou, P. De Laender, T. Bouts, F. Vercammen, R. Ducatelle, A. Smet, F. Haesebrouck
      Helicobacter and Campylobacter species (spp.) colonize the gastrointestinal tract of various domesticated animals. Apart from their pathogenic significance in animals, several species are of zoonotic importance as well. For most non-domesticated animal spp., however, little is known on the presence and importance of these agents. Therefore, we investigated the presence of Helicobacter and Campylobacter spp. in marine and terrestrial zoo mammals. Faecal samples of various marine and terrestrial zoo mammals were collected from 6 different zoos in Belgium. These samples were tested for the presence of Helicobacter and Campylobacter spp. by isolation and direct demonstration of DNA using genus-specific PCRs, followed by sequencing of the obtained amplicons. Helicobacter spp. were detected in 12 and Campylobacter spp. in 5 of the 22 faecal samples from marine mammals. In 4 of 5 dolphins, H. cetorum was demonstrated, a well-known pathogen associated with gastritis and gastric ulceration in marine mammals. C. insulaenigrae was isolated from 4 of 6 sea lions and from 1 of 11 seals. To our knowledge, this is the first description of the presence of C. insulaenigrae on the European mainland. Helicobacter spp. were detected in 5 and Campylobacter spp. (mainly C. jejuni subsp. jejuni and C. coli) in 9 of the 26 faecal samples from terrestrial mammals. Potential novel enterohepatic Helicobacter spp. were detected in both marine and terrestrial zoo mammals. For the first time, the presence of several known and unknown Campylobacter and Helicobacter spp. was demonstrated in the gastrointestinal tract of various marine and terrestrial zoo mammals. Further investigation is needed on the pathogenic and zoonotic importance of these species.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.014
       
  • Porcine monocyte-derived dendritic cells can be differentially activated
           by vesicular stomatitis virus and its matrix protein mutants
    • Authors: Guoyan Sun; Xinkui Fang; Hao Wu; Xinchu Zhou; Yong Ke; Tao Sun
      Abstract: Publication date: Available online 8 April 2018
      Source:Veterinary Microbiology
      Author(s): Guoyan Sun, Xinkui Fang, Hao Wu, Xinchu Zhou, Yong Ke, Tao Sun
      Vesicular stomatitis virus (VSV) can cause serious vesicular lesions in pigs, and the matrix (M) protein is its predominant virulence factor. Dendritic cells (DCs) act as the bridge between innate and adaptive immune responses. However, the susceptibility of porcine DCs to VSV infection and the role of M protein in modulating the function of infected DCs are still poorly defined. Thus, this study aimed to determine the ability of virulent wild-type VSV(wtVSV) and two attenuated M protein variants (VSVΔM51 and VSVMT) to induce maturation of porcine monocyte-derived DCs (MoDCs) in vitro. It was found that both wtVSV and the M protein mutant VSVs could productively replicate in porcine MoDCs. Infection with wtVSV resulted in weak proinflammatory cytokine responses and interfered with DC maturation via downregulation of the costimulatory molecule complex CD80/86. Whilst VSVΔM51 could activate porcine MoDCs, VSVMT, a highly attenuated recombinant VSV with triple mutations in the M protein, induced a potent maturation of MoDCs, as evidenced by efficient cytokine induction, and upregulation of CD80/86 and MHC class II. Overall, our findings reveal that porcine MoDCs are differentially activated by VSV, dependent on the presence of a functional M protein. M protein plays a crucial role in modulating porcine DC-VSV interactions. The data further support the potential use of VSVMT as a vaccine vector for pigs.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.011
       
  • Serine 105 and 120 are important phosphorylation sites for porcine
           reproductive and respiratory syndrome virus N protein function
    • Authors: Yao Chen; Xiulin Xing; Songlin Feng; Shuyi He; Guihong Zhang
      Abstract: Publication date: Available online 7 April 2018
      Source:Veterinary Microbiology
      Author(s): Yao Chen, Xiulin Xing, Songlin Feng, Shuyi He, Guihong Zhang
      The nucleocapsid (N) protein is the most abundant protein of porcine reproductive and respiratory syndrome virus (PRRSV). It has been shown to be multiphosphorylated. However, the phosphorylation sites are still unknown. In this study, we used liquid chromatography tandem mass spectrometry (LC-MS/MS) to analyze the phosphorylation sites of N protein expressed in Sf9 cells. The results showed that N protein contains two phosphorylation sites. Since N protein can regulate IL-10, which may facilitate PRRSV replication, we constructed four plasmids (pCA-XH-GD, pCA-A105, pCA-A120 and pCA-A105-120) and transfected them into Pig alveolar macrophages (PAMs,3D4/2). The qPCR results showed that mutations at residues 105 and 120 were associated with down-regulation of the IL-10 mRNA level, potentially decreasing the viral growth ability. Then, we mutated the phosphorylation sites (S105A and S120A) and rescued three mutated viruses, namely, A105, A120 and A105-120. Compared with wild-type virus titers, the titers of the mutated viruses at 48hpi were significantly decreased. The Nsp(non-structural protein) 9 qPCR results were consistent with the multistep growth kinetics results. The infected PAMs (primary PAMs) results were similar with Marc-145.The findings indicated that the mutations impaired the viral replication ability. The confocal microscopy results suggested that mutations to residues 105 and 120 did not affect N protein distribution. Whether the mutations affected other functions of N protein and what the underlying mechanisms are need further investigation. In conclusion, our results show that residues 105 and 120 are phosphorylation sites and are important for N protein function and for viral replication ability.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.010
       
  • Evaluation of the immune response afforded by a subunit vaccine candidate
           against bluetongue virus in mice and sheep
    • Authors: Darien Kheder Ali Mohamed; Junzheng Du; Shandian Gao; Zhancheng Tian; Guorui Zhang; Dexuan Huang; Rongsheng Du; Biao Kang; Guangyuan Liu; Jianxun Luo; Hong Yin
      Abstract: Publication date: Available online 5 April 2018
      Source:Veterinary Microbiology
      Author(s): Darien Kheder Ali Mohamed, Junzheng Du, Shandian Gao, Zhancheng Tian, Guorui Zhang, Dexuan Huang, Rongsheng Du, Biao Kang, Guangyuan Liu, Jianxun Luo, Hong Yin
      Bluetongue virus (BTV), a vector-borne pathogen, is the causative agent of bluetongue disease in ruminants. In view of the recent emergence of BTV in regions previously known to be free from the disease and/or specific serotypes or strains, optimization of the currently available vaccination strategies to control the spread of vector-borne bluetongue is crucial. The main objective of the current study was to develop a subunit vaccine candidate targeting BTV-16, a strain previously isolated in China from sheep with obvious clinical signs. To this end, five polyhistidine-tagged recombinant proteins (BTV-16 VP2, VP3, VP7, NS2 and a truncated version of VP5 (VP5-41amino acids) were expressed using the baculovirus or Escherichia coli expression system for characterization of protective activity. To determine ovine and murine immune responses to the five proteins, sheep and mice were immunized twice at 4- and 2-week intervals, respectively, with one of two different protein combinations in MontanideTM ISA201 VG adjuvant or placebo. Data from the competitive enzyme linked immunosorbent assay revealed significantly higher antibody titers in immunized than control animals. Expressed VP5 and NS2 induced a protein-specific humoral response. Interestingly, a serum neutralization test against the BTV-1 serotype showed promising cross-serotype immune response by the vaccine. Based on the collective data, we suggest that these recombinant purified proteins present promising candidates for the design of effective novel vaccines against BTV.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.04.007
       
  • Antimicrobial susceptibility and genetic relatedness of respiratory tract
           pathogens in weaner pigs over a 12-month period
    • Authors: Lisa Niemann; Petra Müller; Jasmin Brauns; Rolf Nathaus; Franziska Schäkel; Kerstin Kipschull; Doris Höltig; Michael Wendt; Stefan Schwarz; Kristina Kadlec
      Abstract: Publication date: Available online 4 April 2018
      Source:Veterinary Microbiology
      Author(s): Lisa Niemann, Petra Müller, Jasmin Brauns, Rolf Nathaus, Franziska Schäkel, Kerstin Kipschull, Doris Höltig, Michael Wendt, Stefan Schwarz, Kristina Kadlec
      The collaboration project VASIB aims at reducing the antibiotic consumption in pig production by integrating information from consulting expertise in clinical inspection, hygiene, epidemiology, microbiology and pharmacology. In this VASIB subproject, we investigated the antimicrobial susceptibility and relatedness of porcine respiratory tract pathogens. Bordetella bronchiseptica (n = 47), Pasteurella multocida (n = 18) and Streptococcus suis (n = 58) were obtained from weaner pigs at two farms. Antimicrobial susceptibility testing was performed by broth microdilution according to CLSI standards. Resistance genes were detected via specific PCR assays. Macrorestriction analysis was conducted to determine the relatedness of the isolates and to identify clones. The B. bronchiseptica isolates showed indistinguishable (farm 1) or two closely related XbaI-patterns (farm 2). Different SmaI-PFGE patterns of P. multocida isolates were obtained at three different time points. In contrast, PFGE analysis of S. suis indicated more than one fragment pattern per pig and time point. Isolates exhibiting indistinguishable PFGE patterns were considered to represent the same clone. This study showed that only two closely related B. bronchiseptica clones were present in both farms, which had low MICs to all antimicrobials, except to β-lactams. Different P. multocida clones were present at the three time points. They showed overall low MIC values, with two clones being resistant and one intermediate to tetracycline. S. suis clones were resistant to tetracycline (n = 19) and/or erythromycin/clindamycin (n = 16). They harboured the tetracycline resistance genes tet(O), tet(M) or tet(L) and/or the macrolide/lincosamide/streptogramin B resistance gene erm(B). Five penicillin-resistant S. suis clones were also detected.

      PubDate: 2018-04-15T05:26:15Z
      DOI: 10.1016/j.vetmic.2018.03.030
       
  • Newcastle disease virus-attenuated vaccine co-contaminated with fowl
           adenovirus and chicken infectious anemia virus results in inclusion body
           hepatitis-hydropericardium syndrome in poultry
    • Authors: Qi Su; Yang Li; Fanfeng Meng; Zhizhong Cui; Shuang Chang; Peng Zhao
      Abstract: Publication date: Available online 17 March 2018
      Source:Veterinary Microbiology
      Author(s): Qi Su, Yang Li, Fanfeng Meng, Zhizhong Cui, Shuang Chang, Peng Zhao
      Inclusion body hepatitis-hydropericardium syndrome (IBH-HPS) induced by fowl adenovirus type 4 (FAdV-4) has caused huge economic losses to the poultry industry of China, but the source of infection for different flocks, especially flocks with high biological safety conditions, has remained unclear. This study tested the pathogenicity of Newcastle disease virus (NDV)-attenuated vaccine from a large-scale poultry farm in China where IBH-HPS had appeared with high mortality. Analysis revealed that the NDV-attenuated vaccine in use from the abovementioned poultry farm was simultaneously contaminated with FAdV-4 and chicken infectious anemia virus (CIAV). The FAdV and CIAV isolated from the vaccine were purified for the artificial preparation of an NDV-attenuated vaccine singly contaminated with FAdV or CIAV, or simultaneously contaminated with both of them. Seven-day-old specific pathogen-free chicks were inoculated with the artificially prepared contaminated vaccines and tested for corresponding indices. The experiments showed that no hydropericardium syndrome (HPS) and corresponding death occurred after administering the NDV-attenuated vaccine singly contaminated with FAdV or CIAV, but a mortality of 75% with IBH-HPS was commonly found in birds after administering the NDV-attenuated vaccine co-contaminated with FAdV and CIAV. In conclusion, this study found the co-contamination of FAdV-4 and CIAV in the same attenuated vaccine and confirmed that such a contaminated attenuated vaccine was a significant source of infection for outbreaks of IBH-HPS in some flocks.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.019
       
  • Prophage phiv142-3 enhances the colonization and resistance to
           environmental stresses of Avian Pathogenic Escherichia coli
    • Authors: Dezhi Li; Fang Tang; Feng Xue; Jianluan Ren; Yun Liu; Dehong Yang; Jianjun Dai
      Abstract: Publication date: Available online 17 March 2018
      Source:Veterinary Microbiology
      Author(s): Dezhi Li, Fang Tang, Feng Xue, Jianluan Ren, Yun Liu, Dehong Yang, Jianjun Dai
      Bacterial acquisition of prophages reflects natural selection. Phage DNA has been shown to constitute up to 20% if bacterial genomes. However, prophages’ role in Avian Pathogenic Escherichia coli (APEC) is unclear. In this study, APEC strain DE142 harboring prophage phiv142-3, was subjected to deletion and the WT and deletion mutant were characterized under a range of conditions. Prophage deletion mutant DE142Δphiv142-3 was constructed and characterized. The DE142Δphiv142-3 colonies were much smaller than those of the wild-type, and the mutant cells were elongated. The mutant showed reduced adherence to DF-1 cells (87.4% reduction) compared to the wild-type (P < 0.001), and showed a significantly decreased resistance to the killing action of serum (P < 0.001). The mutant demonstrated 95.6%, 71.6%, and 99.6% reduced survival under acid, alkaline, and oxidative stress, respectively. In vitro competition assays showed that the cell number of the mutant was about one-tenth that of the wild-type (competitive index (CI) value, 0.1177). In vivo, the mutant showed significantly decreased colonization of chicken tissues compared with the wild-type. Thus phiv142-3 helps DE142 cope with adverse environments and aids bacterial colonization.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.017
       
  • T160A mutation-induced deglycosylation at site 158 in hemagglutinin is a
           critical determinant of the dual receptor binding properties of clade
           2.3.4.4 H5NX subtype avian influenza viruses
    • Authors: Ruyi Gao; Min Gu; Kaituo Liu; Qunhui Li; Juan Li; Liwei Shi; Xiuli Li; Xiaoquan Wang; Jiao Hu; Xiaowen Liu; Shunlin Hu; Sujuan Chen; Daxin Peng; Xinan Jiao; Xiufan Liu
      Abstract: Publication date: Available online 17 March 2018
      Source:Veterinary Microbiology
      Author(s): Ruyi Gao, Min Gu, Kaituo Liu, Qunhui Li, Juan Li, Liwei Shi, Xiuli Li, Xiaoquan Wang, Jiao Hu, Xiaowen Liu, Shunlin Hu, Sujuan Chen, Daxin Peng, Xinan Jiao, Xiufan Liu
      Most clade 2.3.4.4 H5NX subtype avian influenza viruses possess a T160A amino acid substitution in the hemagglutinin (HA) protein that has been shown to affect the receptor binding properties of a clade 2.3.4 H5N1 virus. However, the effect of this single site mutation on the HA backbone of clade 2.3.4.4 H5NX viruses remains unclear. In this study, two H5N6 field isolates possessing HA-160A with dual α-2,3 and α-2,6 receptor binding properties (Y6 virus) and HA-160T with α-2,3 receptor binding affinity (HX virus), respectively, were selected to generate HA mutants containing all of the internal genes from A/PR8/H1N1 virus for comparative investigation. We found that the Y6-P-160A and RHX-P-160A viruses each with 160A in the HA resulting in loss of glycosylation at site 158 exhibited binding to the two receptor types, whereas the RY6-P-160T and HX-P-160T viruses each with 160T in the HA displayed selective binding to α-2,3 receptors only. In addition, differences were noted in the replication of these four H5N6 recombinants in avian and mammalian cells, as well as in their pathogenicity in mice. The contribution of deglycosylation at site 158 to the acquisition of human-like receptors was further verified in H5N2, H5N5 and H5N8 reassortants. Therefore, we conclude that the lack of glycosylation at site 158 induced by the T160A mutation in HA is a critical determinant for the dual receptor binding properties of clade 2.3.4.4 H5NX viruses. This new insight may be helpful in assessing the pandemic potential of novel H5 isolates.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.018
       
  • Microbiomes associated with bovine periodontitis and oral health
    • Authors: Ana C. Borsanelli; David F. Lappin; Lorenzo Viora; David Bennett; Iveraldo S. Dutra; Bernd W. Brandt; Marcello P. Riggio
      Abstract: Publication date: Available online 16 March 2018
      Source:Veterinary Microbiology
      Author(s): Ana C. Borsanelli, David F. Lappin, Lorenzo Viora, David Bennett, Iveraldo S. Dutra, Bernd W. Brandt, Marcello P. Riggio
      Periodontitis is an infectious polymicrobial, immuno-inflammatory disease of multifactorial aetiology that has an impact on the health, production and welfare of ruminants. The objective of the present study was to determine the microbial profiles present in the gingival sulcus of cattle considered periodontally healthy and in the periodontal pocket of animals with periodontitis lesions using high-throughput bacterial 16 S rRNA gene sequencing. Subgingival biofilm samples were collected from 40 cattle with periodontitis and 38 periodontally healthy animals. In total, 1923 OTUs were identified and classified into 395 genera or higher taxa. Microbial profiles in health differed significantly from periodontitis in their composition (p <0.0001, F = 5.30; PERMANOVA) but no statistically significant differences were observed in the diversity of healthy and periodontitis microbiomes. The most prevalent taxa in health were Pseudomonas, Burkholderia and Actinobacteria, whereas in disease these were Prevotella, Fusobacterium and Porphyromonas. The most discriminative taxa in health were Gastranaerophilales, Planifilum and Burkholderia, and in disease these were Elusimicrobia, Synergistes and Propionivibrio. In conclusion, statistically significant difference exists between the microbiome in bovine oral health and periodontitis, with populations showing 72.6% dissimilarity. The diversity of the bacteria found in health and periodontitis were similar and bacteria recognised as periodontal pathogens showed increased abundance in disease. In this context, the main components of bacterial homeostasis in the biofilm of healthy sites and of dysbiosis in periodontal lesions provide unprecedented indicators for the evolution of knowledge about bovine periodontitis.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.016
       
  • Evaluation of bovine viral diarrhea virus transmission potential to naïve
           calves by direct and indirect exposure routes
    • Authors: Shollie M. Falkenberg; Rohana P. Dassanayake; John D. Neill; Julia F. Ridpath
      Abstract: Publication date: Available online 16 March 2018
      Source:Veterinary Microbiology
      Author(s): Shollie M. Falkenberg, Rohana P. Dassanayake, John D. Neill, Julia F. Ridpath
      Bovine viral diarrhea viruses (BVDV) can cause both acute and persistent infections in cattle. Exposure to BVDV persistently infected (PI) animals results in transmission of the virus to a naïve animal which causes a transient acute infection. While it is known that direct exposure to PI animals is a highly efficient means of transmission, less information is available regarding the potential for transmission from acutely infected either by direct or indirect exposure to naïve animals. Therefore, the objective of this study was to evaluate the potential for spread of the virus from calves acutely infected, with typical virulence field viruses know to have minimal shedding and viremia, to naïve contact animals either by direct or indirect exposure. To accomplish this objective, two BVDV isolates belonging to two species of BVDV, type 1 and type 2, were used to inoculate calves. Subsequently on day 2 post-infection, naïve calves were exposed to inoculated calves, either directly or indirectly, over a period of two weeks. All calves were evaluated for the presence of virus in blood samples and nasal swabs, pyrexia, lymphopenia and seroconversion. BVDV was isolated from inoculated calves but not from any of the direct and indirect contact animals or from control calves. Similarly, pyrexia and lymphopenia were observed in the inoculated calves, but not in contact and control calves. Only the inoculated calves seroconverted by day 38 of the study indicating that no transmission had occurred to the naïve contact calves. This data would suggest that there may be an infectious dose needed for transmission of virus for typical virulent isolates.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.012
       
  • Antimicrobial usage and presence of extended-spectrum
           β-lactamase-producing Enterobacteriaceae in animal-rearing households of
           selected rural and peri-urban communities
    • Authors: Evelyn O. Okpara; Olufemi E. Ojo; Olajoju J. Awoyomi; Morenike A. Dipeolu; Mufutau A. Oyekunle; Stefan Schwarz
      Abstract: Publication date: Available online 14 March 2018
      Source:Veterinary Microbiology
      Author(s): Evelyn O. Okpara, Olufemi E. Ojo, Olajoju J. Awoyomi, Morenike A. Dipeolu, Mufutau A. Oyekunle, Stefan Schwarz
      This study examined socioeconomic and cultural factors relating to animal husbandry, antimicrobial usage and household hygiene in 320 animal-keeping households of 16 rural and peri-urban communities of Ogun State, Nigeria. The occurrence of extended-spectrum β-lactamase-producing Enterobacteriaceae in 457 samples from animal and environmental sources within the households was investigated. Chickens (41.6%), goats (35.3%), dogs (33.8%) and sheep (14.4%) were the most common household animals. Animals were reared mainly for income generation (73.9%) and for household consumption (18.3%). They were reared predominantly (60.2% - 100%) under the extensive system with unrestricted access to human space, cooking utensils and foods. Households were assessed as having good (59.4%), fair (22.2%) and poor (18.4%) hygiene. The rate of household non-prescriptional antimicrobial usage was 69.4% in humans and 60.6% in animals. Overall, ESBL-producing Enterobacteriaceae were detected in 53 (11.6%) of 457 samples. The ESBL-producing isolates were identified as Escherichia coli (n = 49) and Klebsiella pneumoniae (n = 4). They harboured the ESBL gene variants bla CTX-M-15 (n = 49), bla CTX-M-14 (n = 2), bla CTX-M-27 (n = 1) or bla CTX-M-55 (n = 1). Forty-eight ESBL-producing E. coli were assigned into phylogenetic groups A (n = 17), B1 (n = 14), D (n = 13) and F (n = 4). All ESBL-producing isolates demonstrated multidrug resistance to antimicrobial agents belonging to at least three different classes of antimicrobials. Poor regulation of antimicrobial marketing and inadequate access to veterinary care contributed to non-prescriptional use of antimicrobials in humans and animals. Free-range household animals harboured ESBL-producing bacteria and may facilitate the dispersal of the organisms within the community.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.013
       
  • A Two Dose Immunization With An Inactivated Reassortant H5N2 Virus
           Protects Chickens Against Lethal Challenge With Homologous 2.3.2.1 Clade
           
    • Authors: Sushant Bhat; Richa Sood; Shweta Shukla; Rekha Khandia; Atul Kumar Pateriya; Naveen Kumar; Vikas Kumar Singh; Semmannan Kalaiyarasu; Manoj Kumar; Sandeep Bhatia
      Abstract: Publication date: Available online 13 March 2018
      Source:Veterinary Microbiology
      Author(s): Sushant Bhat, Richa Sood, Shweta Shukla, Rekha Khandia, Atul Kumar Pateriya, Naveen Kumar, Vikas Kumar Singh, Semmannan Kalaiyarasu, Manoj Kumar, Sandeep Bhatia
      The present study was aimed at generating a reassortant vaccine candidate virus with clade 2.3.2.1 Hemagglutinin (HA) and its evaluation in a challenge study for protection against homologous (2.3.2.1 clade) and heterologous (2.2 clade) highly pathogenic avian influenza (HPAI) H5N1 viruses. Plasmid-based reverse genetics technique was used to rescue a 5 + 3 reassortant H5N2 strain containing the modified HA of H5N1 (clade 2.3.2.1), the Neuraminidase (NA) of H9N2, the Matrix (M) of H5N1 and the internal genes of A/WSN/33 H1N1. In addition, another 6 + 2 reassortant virus containing modified HA from H5N1 (clade 2.3.2.1), the NA from H9N2 and the internal genes of A/WSN/33 H1N1 was also rescued. The 5 + 3 reassortant H5N2 virus could grow to a higher titer in both MDCK cells and chicken eggs compared to the 6 + 2 reassortant H5N2 virus. The vaccine containing the inactivated 5 + 3 reassortant H5N2 virus was used in a two-dose immunization regime which protected specific pathogen free (SPF) chickens against two repeated challenges with homologous 2.3.2.1 clade and heterologous 2.2 clade HPAI H5N1 viruses. The 5 + 3 reassortant H5N2 virus based on clade 2.3.2.1 generated in this study can be effective in protecting chickens in the case of an outbreak caused by antigenically different clade 2.2 HPAI H5N1 viruses and opens the way to explore its applicability as potential vaccine candidate especially in the Asian countries reporting these clades frequently. The study also indicates that sequential immunization can broaden protection against antigenically diverse strains of H5N1 viruses.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.004
       
  • From the [Pasteurella] pneumotropica complex to Rodentibacter spp.: an
           update on [Pasteurella] pneumotropica
    • Authors: Laurentiu Benga; Martin Sager; Henrik Christensen
      Abstract: Publication date: Available online 12 March 2018
      Source:Veterinary Microbiology
      Author(s): Laurentiu Benga, Martin Sager, Henrik Christensen
      The species [Pasteurella] pneumotropica has been reclassified into the new genus Rodentibacter, within the family Pasteurellaceae. Along with the type species (Rodentibacter pneumotropicus) of the new genus, seven new species have been named. These organisms were formerly mainly known as the [P.] pneumotropica complex and [P.] pneumotropica was considered as the most important Pasteurellaceae species colonizing laboratory rodents. The aim of this review is to update the veterinary relevant aspects of clinical manifestations, pathogenesis, virulence and diagnostics of members of Rodentibacter with a focus on the most important species from a veterinary perspective. The organisms are obligate commensals of the mucous membranes and members of Rodentibacter are not able to persist for long in the environment. Members of Rodentibacter spp. are responsible for the most prevalent bacterial infections in laboratory mice and rats, but are also common in rodents outside laboratory settings. Some Rodentibacter spp. produce mainly localised disease in connection with favouring factors and seldomly act as primary pathogens in healthy immunocompetent animals. The subclinical infection with Rodentibacter spp. can affect the results of certain types of research using contaminated animals thus placing them on a list of microbes which are often not tolerated in experimental rodent facilities. The presences of RTX toxins, YadA-like proteins and a capsule with possible role in the pathogenesis have been described. Some species of Rodentibacter are able to form robust biofilms which might be involved in colonisation and persistence within the host. Current possibilities for diagnostics and differentiation among Rodentibacter spp. are outlined and options for treatment and control are provided.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.011
       
  • Vaccination with outer membrane vesicles and the fimbrial protein FlfA
           offers improved protection against lesions following challenge with
           Gallibacterium anatis
    • Authors: Gry Persson; Susanne E. Pors; Ida C.N. Thøfner; Anders M. Bojesen
      Abstract: Publication date: Available online 12 March 2018
      Source:Veterinary Microbiology
      Author(s): Gry Persson, Susanne E. Pors, Ida C.N. Thøfner, Anders M. Bojesen
      Gallibacterium anatis is an opportunistic poultry pathogen belonging to the Pasteurellaceae family. It has been shown to cause oophoritis, salpingitis and peritonitis in hens, as well as being associated with reduced semen quality in cockerels. Widespread multidrug resistance and substantial antigenic variation among strains of Gallibacterium anatis is a major constraint to treatment with antimicrobials and prevention of infection by vaccination. Novel vaccine strategies targeting G. anatis are therefore necessary. Outer membrane vesicles (OMVs) are nanosized vesicles formed from the outer membrane of Gram-negative bacteria. These vesicles have shown promising potential as both adjuvants and as vaccine candidates against numerous bacterial species. A high vesiculating mutant of G. anatis (G. anatis ΔtolR ) has previously been made, enabling production of OMVs in large scale. In this study, we elucidated the potential of G. anatis ΔtolR OMVs as adjuvant for the conserved antigens GtxA-N (the N-terminal part of the RTX like toxin Gallibacterium toxin A) and FlfA (F17-like fimbria), as well as evaluated if combinations of OMVs together with antigens could facilitate cross-protective immunity against three different strains of G. anatis. We showed that ΔtolR OMVs function as an adjuvant for GtxA-N by inducing antigen specific antibody production. However, OMVs in combination with GtxA-N failed to induce protection against lesions after challenge infection. In contrast, vaccination with OMVs in combination with FlfA protected against lesions, especially in the salpinx, caused by two diverse strains of G. anatis, thereby indicating a cross-protective potential. No protection against the third G. anatis strain 7990 could be obtained in any of the experimental settings. In conclusion, ΔtolR OMVs and FlfA could serve as potential future vaccine components againt G. anatis.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.010
       
  • Consecutive antibiotic treatment with doxycycline and marbofloxacin clears
           bacteremia in Mycoplasma haemofelis-infected cats
    • Authors: Marilisa Novacco; Sarah Sugiarto; Barbara Willi; Julia Baumann; Andrea M. Spiri; Angelina Oestmann; Barbara Riond; Felicitas S. Boretti; Hanspeter Naegeli; Regina Hofmann-Lehmann
      Abstract: Publication date: Available online 10 March 2018
      Source:Veterinary Microbiology
      Author(s): Marilisa Novacco, Sarah Sugiarto, Barbara Willi, Julia Baumann, Andrea M. Spiri, Angelina Oestmann, Barbara Riond, Felicitas S. Boretti, Hanspeter Naegeli, Regina Hofmann-Lehmann
      Mycoplasma haemofelis is the most pathogenic feline hemoplasma species and a causative agent of infectious hemolytic anemia in cats. Current treatment protocols are effective in reducing M. haemofelis blood loads and clinical signs but consistent bacteremia clearance is rarely achieved. The aim of this study was to develop an antibiotic treatment protocol capable of clearing M. haemofelis bacteremia. Doxycycline and marbofloxacin treatment protocols were evaluated in chronically M. haemofelis infected cats in two pre-experiments and a controlled treatment study (main experiment) using five treated and four untreated cats. The blood bacterial loads in the main experiment were monitored weekly by real-time PCR for 203 days. Cats were treated with doxycycline (5 mg/kg bid orally) for 28 days. Cats that remained M. haemofelis PCR-positive or became positive again (all 5 cats in the main experiment) were switched to marbofloxacin treatment (2 mg/kg sid orally) for 14 days; then, all cats were PCR-negative. Immunosuppression after the antibiotic treatment did not lead to reactivation of bacteremia. Fine needle aspirates of different organs and bone marrow collected before and after immunosuppression were PCR-negative. Overall, 5 cats cleared bacteremia with doxycycline alone (showing lower bacterial loads at the treatment start), while 10 cats needed to be switched to marbofloxacin. Based on our results, we recommend doxycycline treatment (10 mg/kg up to 28 days) for clearance of M. haemofelis infection and monitoring bacterial loads by real-time PCR. Only if bacteremia persists or reoccurs, antibiotic treatment should be switched to marbofloxacin (2 mg/kg sid for 14 days).

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.006
       
  • Understanding the health and production impacts of endemic Chlamydia
           pecorum infections in lambs
    • Authors: Evelyn Walker; Martina Jelocnik; Sankhya Bommana; Peter Timms; Scott Carver; Adam Polkinghorne
      Abstract: Publication date: Available online 10 March 2018
      Source:Veterinary Microbiology
      Author(s): Evelyn Walker, Martina Jelocnik, Sankhya Bommana, Peter Timms, Scott Carver, Adam Polkinghorne
      Chlamydia pecorum, is a globally recognised livestock pathogen that is capable of causing severe and economically significant diseases such as arthritis in sheep and cattle. Relatively little information is available on the clinical progression of disease and the long-term effects of asymptomatic and symptomatic chlamydiosis in sheep. Recent studies in calves indicate that endemic C. pecorum infections may reduce growth rates. To investigate the clinical health parameters and production impacts of endemic C. pecorum infection in an Australian commercial lamb flock, we performed bimonthly sampling and clinical health assessments on 105 Border Leicester lambs from two to ten months of age. Chlamydial status was investigated via serology and species-specific quantitative PCR. Throughout the study period, conjunctivitis remained a persistent clinical feature while signs of arthritis (e.g. palpable synovial joint effusions) resolved in a subset of lambs while persisting in others. Clinical disease and C. pecorum infection were highest at six months of age (weaning). As previously reported, peak seroconversion tends to occur two months after the onset of clinical symptoms (6 months of age), with lambs clearing chlamydial infection by 10 months of age, despite ongoing disease still being present at this time. Notably, the presence of chlamydial infection did not affect lamb mass or growth rates throughout the study. At necropsy, C. pecorum was not detected within the joints of lambs with chronic arthritis. Molecular analysis of the strains in this flock suggest that the infecting strains circulating in this flock are clonal C. pecorum pathotypes, denoted ST 23, commonly associated with conjunctivitis and polyarthritis in Australian sheep. This study provides a platform for further research in the epidemiology and disease transmission dynamics of C. pecorum infections in sheep.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.009
       
  • Transmission and pathogenicity of Gallibacterium anatis and Escherichia
           coli in embryonated eggs
    • Authors: Chong Wang; Susanne Elisabeth Pors; Rikke Heidemann Olsen; Anders Miki Bojesen
      Abstract: Publication date: Available online 10 March 2018
      Source:Veterinary Microbiology
      Author(s): Chong Wang, Susanne Elisabeth Pors, Rikke Heidemann Olsen, Anders Miki Bojesen
      In laying hens, Escherichia coli (E. coli) and Gallibacterium anatis (G. anatis) are considered the two major pathogens causing reproductive tract disorders, either as single infections or as co-infections. Vertical transmission has been confirmed for E. coli but remains to be clearly demonstrated for G. anatis. The aim of the present study was to investigate the ability of both G. anatis and E. coli at eggshell transmission using an embryonated egg dipping model, and to investigate the possible interaction between the two organisms in an embryonated egg injection model. Embryonated eggs were dipped into brain heart infusion broth containing 108 CFU/ml either of G. anatis 12656-12 liver, E. coli ST95 or E. coli ST141, respectively. E. coli ST95 and ST141 were re-isolated from the interior egg contents in 60% (12/20) and 85% (17/20) of the eggs, respectively, while G. anatis 12656-12 was only re-isolated from the interior egg contents in 6.7% (3/45) eggs. Eggs were injected with 10 to 1000 CFU of either G. anatis 12656-12, E. coli ST95 or ST141 into the allantoic cavity. As few as 10 CFU of G. anatis 12656-12 resulted in 100% mortality within 24 hours post injection whereas the E. coli injected embryos all died at 48 hours post injection. Significant difference in CFU counts were observed for G. anatis when compared G. anatis injection group with either of the two G. anatis – E. coli co-injection groups. Sixteen hours post injection, a significant difference in embryo mortality could be observed when comparing co-injected embryonated eggs (G. anatis and E. coli) and single-injected (G. anatis or E. coli) embryonated eggs. In conclusion, bacterial transmission via the eggshell was demonstrated for both G. anatis and E. coli although at different magnitudes. The embryonated egg injection model revealed that G. anatis in particular was highly pathogenic when exposed directly to the developing embryo.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.005
       
  • New insights on pestivirus infections in transhumant sheep and sympatric
           Pyrenean chamois (Rupicapra p. pyrenaica)
    • Authors: Andreu Colom-Cadena; Johan Espunyes; Oscar Cabezón; Xavier Fernández-Aguilar; Rosa Rosell; Ignasi Marco
      Abstract: Publication date: Available online 9 March 2018
      Source:Veterinary Microbiology
      Author(s): Andreu Colom-Cadena, Johan Espunyes, Oscar Cabezón, Xavier Fernández-Aguilar, Rosa Rosell, Ignasi Marco
      Border Disease Virus (BDV) causes health and economic impact on livestock and is also of importance in wildlife conservation as it causes high mortality outbreaks in Pyrenean chamois (Rupicapra pyrenaica pyrenaica). Pastoral practices are known as a main interspecies pathogen transmission. Hence, the presence of pestivirus in transhumant sheep flocks and sympatric chamois was assessed in areas with different epidemiological scenarios of chamois BDV infections. Moreover, the present study had also the goal to identify if inter-specific infections occurred and when they happened. Five sheep flocks grazing in two alpine areas in the Pyrenees with two different BDV epidemiological scenarios in chamois populations were studied during two transhumant seasons. Sheep were sampled before and after transhumance. Pyrenean chamois sera and spleen samples from both areas where also studied during the same period. Antibodies against BDV were assessed by means of ELISA and VNT. A qRT-PCR was used in order to detect the virus. Seroprevalence in sheep ranged between 0 and 91.1% at the flock level. Chamois were found to have high seroprevalences (52.9-77.7%) in both areas, and four new BDV isolates were sequenced. One sheep farm presented persistent BDV circulation and three showed low BDV circulation. The after-transhumance period was identified as the moment when viral transmission occured in the first farm, associated to BDV strains of domestic origin, according to VNT results. However, the BDV isolate was genetical closely related to previous BDV strains from chamois origin. In another farm, antibodies in two of the three positive sera were associated to infection with a chamois-like BDV strain. Altogether indicates that occasional viral transmission from chamois to sheep may occur.

      PubDate: 2018-03-19T04:34:51Z
      DOI: 10.1016/j.vetmic.2018.03.003
       
  • New trends in innovative vaccine development against Actinobacillus
           pleuropneumoniae
    • Authors: Abraham Loera-Muro; Carlos Angulo
      Abstract: Publication date: Available online 6 March 2018
      Source:Veterinary Microbiology
      Author(s): Abraham Loera-Muro, Carlos Angulo
      Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, a respiratory disease leading to severe economic losses in the swine industry. The most widely used commercial vaccines are bacterins comprising inactivated whole cells of A. pleuropneumoniae but these have only been partially effective in preventing disease. Innovative immuno-prophylactic preparations of A. pleuropneumoniae based on ApxI, ApxII, ApxIII, ApxIV toxins and outer membrane proteins, among others (i.e. RnhB, GalU, GalT, HflX, ComL, LolB, LppC), have high protective efficacy in mice and pigs. Some vaccine preparations have efficacy against homologous and heterologous A. pleuropneumoniae serovars, which constitute an important advance to control porcine pleuropneumonia. In this arena, subunit vaccines based on toxins are one of the most advanced and promising developments. Many research groups have focussed on the development of live attenuated vaccines comprising strains with inactivated Apx toxins and/or other virulence factors, their protective efficacy being determined in mouse and/or swine models. Other innovative approaches such as bacteria, yeast and plants as production and oral delivery platforms have been explored in animal models and the definitive host with encouraging results. In addition, further research into A. pleuropneumoniae-based DNA and nano-vaccines, as well as bioencapsulation of antigens in plants, is envisaged. Here, the recent findings and future trends in innovative vaccine development against A. pleuropneumoniae are reviewed and placed in perspective.

      PubDate: 2018-03-07T04:08:42Z
      DOI: 10.1016/j.vetmic.2018.02.028
       
  • The major membrane nuclease MnuA degrades neutrophil extracellular traps
           induced by Mycoplasma bovis
    • Authors: Filimon Mitiku; Carol A. Hartley; Fiona M. Sansom; Joanne E. Coombe; Peter D. Mansell; David S. Beggs; Glenn F. Browning
      Abstract: Publication date: Available online 5 March 2018
      Source:Veterinary Microbiology
      Author(s): Filimon Mitiku, Carol A. Hartley, Fiona M. Sansom, Joanne E. Coombe, Peter D. Mansell, David S. Beggs, Glenn F. Browning
      Mycoplasma bovis has been increasingly recognised worldwide as an economically important pathogen of cattle, causing a range of diseases, including pneumonia, mastitis, polyarthritis and otitis media. It is believed that M. bovis utilises a range of cell surface proteins, including nucleases, to evade the host immune response and survive. However, despite the importance of neutrophils in controlling pathogenic bacteria, the interaction between these cells and M. bovis is not well-characterised. In addition to phagocytosis, neutrophils combat pathogens through the release of neutrophil extracellular traps (NETs), which are composed of their nuclear and granular components, including DNA. Here we investigated the effect of the major membrane nuclease MnuA of M. bovis, which in vitro is responsible for the majority of the nuclease activity of M. bovis, on NET formation. We quantified NET formation by bovine neutrophils 4 hours after stimulation with wild-type M. bovis, an mnuA mutant and a mnuA-pIRR45 complemented mnuA mutant. NETs were detected following stimulation of neutrophils with the mnuA mutant but not after exposure to either the wild-type or the mnuA-pIRR45 complemented mutant, and NETs were degraded in the presence of even low concentrations of wild type M. bovis. Surprisingly, there was no increase in levels of intracellular reactive oxygen species (ROS) production in neutrophils stimulated with M. bovis, even though these neutrophils produced NETs. These results clearly demonstrate that M. bovis can induce NET formation in bovine neutrophils, but that the major membrane nuclease MnuA is able to rapidly degrade NETs, and thus is likely to play a significant role in virulence. In addition, M. bovis appears to induce NETs even though ROS production seems to be suppressed.

      PubDate: 2018-03-07T04:08:42Z
      DOI: 10.1016/j.vetmic.2018.03.002
       
  • Evaluating the most appropriate pooling ratio for EDTA blood samples to
           detect Bluetongue virus using real-time RT-PCR
    • Authors: John Flannery; Paulina Rajko-Nenow; Hayley Hicks; Holly Hill; Simon Gubbins; Carrie Batten
      Abstract: Publication date: Available online 3 March 2018
      Source:Veterinary Microbiology
      Author(s): John Flannery, Paulina Rajko-Nenow, Hayley Hicks, Holly Hill, Simon Gubbins, Carrie Batten
      The control of Bluetongue virus (BTV) presents a significant challenge to European Union (EU) member states as trade restrictions are placed on animals imported from BTV-affected countries. BTV surveillance programs are costly to maintain, thus, pooling of EDTA blood samples is used to reduce costs and increase throughput. We investigated different pooling ratios (1:2, 1:5, 1:10 and 1:20) for EDTA blood samples to detect a single BTV positive animal. A published real-time RT-PCR assay (Hofmann et al., 2008) and a commercial assay (ThermoFisher VetMax™ BTV NS3 kit) were used to analyse BTV RNA extracted from pooled EDTA blood samples. The detection rate was low for the onset of infection sample (0 to 2 days post infection (dpi); CT 36) irrespective of the pooling ratio. Both assays could reliably detect a single BTV-positive animal at early viraemia (3 to 6 dpi; CT 33) when pooled, however, detection rate diminished with increasing pooling ratio. A statistical model indicated that pooling samples up to 1:20, is suitable to detect a single BTV positive animal at peak viraemia (7-12 dpi) or late infection (13-30 dpi) with a probability of detection of >80% and >94% using the Hofmann et al. (2008) and VetMAX assays, respectively. Using the assays highlighted in our study, pooling at ratios of 1:20 would be technically suitable in BTV-endemic countries for surveillance purposes. As peak viraemia occurs between 7 to 12 days post infection, a 1:10 pooling ratio is appropriate for post-import testing when animals are sampled within a similar time frame post-import.

      PubDate: 2018-03-07T04:08:42Z
      DOI: 10.1016/j.vetmic.2018.03.001
       
 
 
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